Holliston Test Laboratories does heat testing (HT) and stress testing (ST) on materials and operates at capacity. Under its current simple costing system, Holliston aggregates all operating costs of $975,000 into a single overhead cost pool. Holliston calculates a rate per test-hour of $13 ($975,000 75,000 total test-hours). HT uses 55,000 test-hours, and ST uses 20,000 test-hours. Gary Savarese, Holliston's controller, believes that there is enough variation in test procedures and cost structures to establish separate costing and billing rates for HT and ST. The market for test services is becoming competitive. Without this information, any miscosting and mispricing of its services could cause Holliston to lose business. Savarese divides Holliston's costs into four activity-cost categories.